Even though fiber composite materials are already employed to a large extent in the construction of aircrafts, today many aircraft structure components are made of metallic material, such as aluminium, wherein separate parts of said aircraft structure components, such as the outer skin and the support structure elements, e.g. frames and stringers, are connected to one another by means of rivets, as rivet connections are reliable and considerably easy to establish between two metallic parts. However, such rivet connections usually involve the problem that during the process of riveting recesses are formed on the surface of the parts which are connected to one another, in particular in the outer surface of the outer skin, whereby a certain asperity is introduced into said surface. More detailed, said recesses are usually located adjacent to a rivet received in the outer skin, on that side of the rivet head which is opposite to the rivet shank, i.e. on that end of the rivet hole next to the outer skin's outer surface of the associated aircraft structure component.
Moreover, even when other types of connections such as welds are employed, these connections often result in a recess in the outer surface of the parts involved as well. Therefore, the present invention is not limited to the application to the region around rivet connections.
Such asperity in the outer skin's outer surface causes an unpleasant appearance of said outer surface, as due to said asperity a glimmer in the shape of a half moon is formed on the outer skin at the location of each recess which half moon becomes particularly visible after a reflecting layer of varnish has been applied to the surface.
Further, such asperity is disadvantageous in view of the flight characteristics of the respective aircraft, as the air circulating around said aircraft structure component is slightly vortexed and decelerated by said recesses, thereby slightly increasing the drag of said aircraft, said drag in turn causing the fuel consumption of the aircraft to increase and the maximum range to decrease.
For these reasons it is known in the art of aircraft construction to fill said recesses manually by means of a filling material and a spattle. Yet, such manual filling of the recesses is considerably time-consuming and expensive. Moreover, it is complicated to obtain proper results in that way.